Ligands are being synthesised for affinity chromatography of hexokinase and pyruvate kinase. The purified enzymes will be studied by fluorescent probe analysis for conformational changes induced by metal cations, their substrates and products. The effects of controlled hypoxia (7 percent oxygen) on the kinetic properties of hexose uptake to the brain will be studied in vitro (in slices and in synaptosomes). Attempts will be made to determine if the activities of three glycolytic enzymes (hexokinase, pyruvate kinase and phosphofructokinase) are effected by conditions (hypoxia, anaesthesia, insulin) which change cerebral glycolytic rates.